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haproxy/src/acl.c
Willy Tarreau 3d536ac378 BUG/MINOR: acl: fix sample expression error reporting 
ACL parse errors are not easy to understand since recent commit 348971e
(MEDIUM: acl: use the fetch syntax 'fetch(args),conv(),conv()' into the
ACL keyword) :

[ALERT] 339/154717 (26437) : parsing [check-bug.cfg:10] : error detected while parsing a 'stats admin' rule : unknown ACL or sample keyword 'env(a,b,c)': invalid arg 2 in fetch method 'env' : end of arguments expected at position 2, but got ',b,c'..

This error is only relevant to sample fetch keywords, so the new form is
a bit easier to understand :

[ALERT] 339/160011 (26626) : parsing [check-bug.cfg:12] : error detected while parsing a 'stats admin' rule : invalid arg 2 in fetch method 'env' : end of arguments expected at position 2, but got ',b,c' in sample expression 'env(a,b,c),upper'.

No backport is needed.
2013-12-06 16:02:46 +01:00

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/*
* ACL management functions.
*
* Copyright 2000-2013 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <common/config.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <common/uri_auth.h>
#include <types/global.h>
#include <proto/acl.h>
#include <proto/arg.h>
#include <proto/auth.h>
#include <proto/channel.h>
#include <proto/log.h>
#include <proto/pattern.h>
#include <proto/proxy.h>
#include <proto/sample.h>
#include <proto/stick_table.h>
#include <ebsttree.h>
/* List head of all known ACL keywords */
static struct acl_kw_list acl_keywords = {
.list = LIST_HEAD_INIT(acl_keywords.list)
};
/* input values are 0 or 3, output is the same */
static inline enum acl_test_res pat2acl(enum pat_match_res res)
{
return (enum acl_test_res)res;
}
/*
* Registers the ACL keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void acl_register_keywords(struct acl_kw_list *kwl)
{
LIST_ADDQ(&acl_keywords.list, &kwl->list);
}
/*
* Unregisters the ACL keyword list <kwl> from the list of valid keywords.
*/
void acl_unregister_keywords(struct acl_kw_list *kwl)
{
LIST_DEL(&kwl->list);
LIST_INIT(&kwl->list);
}
/* Return a pointer to the ACL <name> within the list starting at <head>, or
* NULL if not found.
*/
struct acl *find_acl_by_name(const char *name, struct list *head)
{
struct acl *acl;
list_for_each_entry(acl, head, list) {
if (strcmp(acl->name, name) == 0)
return acl;
}
return NULL;
}
/* Return a pointer to the ACL keyword <kw>, or NULL if not found. Note that if
* <kw> contains an opening parenthesis, only the left part of it is checked.
*/
struct acl_keyword *find_acl_kw(const char *kw)
{
int index;
const char *kwend;
struct acl_kw_list *kwl;
kwend = strchr(kw, '(');
if (!kwend)
kwend = kw + strlen(kw);
list_for_each_entry(kwl, &acl_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if ((strncmp(kwl->kw[index].kw, kw, kwend - kw) == 0) &&
kwl->kw[index].kw[kwend-kw] == 0)
return &kwl->kw[index];
}
}
return NULL;
}
static struct acl_expr *prune_acl_expr(struct acl_expr *expr)
{
struct arg *arg;
pattern_prune_expr(&expr->pat);
for (arg = expr->smp->arg_p; arg; arg++) {
if (arg->type == ARGT_STOP)
break;
if (arg->type == ARGT_STR || arg->unresolved) {
free(arg->data.str.str);
arg->data.str.str = NULL;
arg->unresolved = 0;
}
}
if (expr->smp->arg_p != empty_arg_list)
free(expr->smp->arg_p);
return expr;
}
/* Parse an ACL expression starting at <args>[0], and return it. If <err> is
* not NULL, it will be filled with a pointer to an error message in case of
* error. This pointer must be freeable or NULL. <al> is an arg_list serving
* as a list head to report missing dependencies.
*
* Right now, the only accepted syntax is :
* <subject> [<value>...]
*/
struct acl_expr *parse_acl_expr(const char **args, char **err, struct arg_list *al)
{
__label__ out_return, out_free_expr, out_free_pattern;
struct acl_expr *expr;
struct acl_keyword *aclkw;
struct pattern *pattern;
int opaque, patflags;
const char *arg;
struct sample_expr *smp = NULL;
const char *p;
int idx = 0;
char *ckw = NULL;
const char *begw;
const char *endw;
unsigned long prev_type;
int cur_type;
/* First, we lookd for an ACL keyword. And if we don't find one, then
* we look for a sample fetch keyword.
*/
aclkw = find_acl_kw(args[0]);
if (!aclkw || !aclkw->parse) {
smp = sample_parse_expr((char **)args, &idx, trash.str, trash.size, al);
if (!smp) {
memprintf(err, "%s in sample expression '%s'", trash.str, *args);
goto out_return;
}
}
expr = (struct acl_expr *)calloc(1, sizeof(*expr));
if (!expr) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_return;
}
pattern_init_expr(&expr->pat);
expr->kw = aclkw ? aclkw->kw : smp->fetch->kw;
expr->pat.parse = aclkw ? aclkw->parse : NULL;
expr->pat.match = aclkw ? aclkw->match : NULL;
expr->smp = aclkw ? NULL : smp;
if (!expr->pat.parse) {
/* some types can be automatically converted */
switch (expr->smp ? expr->smp->fetch->out_type : aclkw->smp->out_type) {
case SMP_T_BOOL:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_BOOL];
expr->pat.match = pat_match_fcts[PAT_MATCH_BOOL];
break;
case SMP_T_SINT:
case SMP_T_UINT:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_INT];
expr->pat.match = pat_match_fcts[PAT_MATCH_INT];
break;
case SMP_T_IPV4:
case SMP_T_IPV6:
expr->pat.parse = pat_parse_fcts[PAT_MATCH_IP];
expr->pat.match = pat_match_fcts[PAT_MATCH_IP];
break;
}
}
/* now parse the rest of acl only if "find_acl_kw" match */
if (aclkw) {
/* build new sample expression */
expr->smp = calloc(1, sizeof(struct sample_expr));
if (!expr->smp) {
memprintf(err, "out of memory when parsing ACL expression");
goto out_return;
}
LIST_INIT(&(expr->smp->conv_exprs));
expr->smp->fetch = aclkw->smp;
expr->smp->arg_p = empty_arg_list;
/* look for the begining of the subject arguments */
p = strchr(args[0], ',');
arg = strchr(args[0], '(');
if (p && arg && p < arg)
arg = NULL;
if (expr->smp->fetch->arg_mask) {
int nbargs = 0;
char *end;
if (arg != NULL) {
/* there are 0 or more arguments in the form "subject(arg[,arg]*)" */
arg++;
end = strchr(arg, ')');
if (!end) {
memprintf(err, "missing closing ')' after arguments to ACL keyword '%s'", expr->kw);
goto out_free_expr;
}
/* Parse the arguments. Note that currently we have no way to
* report parsing errors, hence the NULL in the error pointers.
* An error is also reported if some mandatory arguments are
* missing. We prepare the args list to report unresolved
* dependencies.
*/
al->ctx = ARGC_ACL;
al->kw = expr->kw;
al->conv = NULL;
nbargs = make_arg_list(arg, end - arg, expr->smp->fetch->arg_mask, &expr->smp->arg_p,
err, NULL, NULL, al);
if (nbargs < 0) {
/* note that make_arg_list will have set <err> here */
memprintf(err, "in argument to '%s', %s", expr->kw, *err);
goto out_free_expr;
}
if (!expr->smp->arg_p)
expr->smp->arg_p = empty_arg_list;
if (expr->smp->fetch->val_args && !expr->smp->fetch->val_args(expr->smp->arg_p, err)) {
/* invalid keyword argument, error must have been
* set by val_args().
*/
memprintf(err, "in argument to '%s', %s", expr->kw, *err);
goto out_free_expr;
}
arg = end;
}
else if (ARGM(expr->smp->fetch->arg_mask) == 1) {
int type = (expr->smp->fetch->arg_mask >> 4) & 15;
/* If a proxy is noted as a mandatory argument, we'll fake
* an empty one so that acl_find_targets() resolves it as
* the current one later.
*/
if (type != ARGT_FE && type != ARGT_BE && type != ARGT_TAB) {
memprintf(err, "ACL keyword '%s' expects %d arguments", expr->kw, ARGM(expr->smp->fetch->arg_mask));
goto out_free_expr;
}
/* Build an arg list containing the type as an empty string
* and the usual STOP.
*/
expr->smp->arg_p = calloc(2, sizeof(*expr->smp->arg_p));
expr->smp->arg_p[0].type = type;
expr->smp->arg_p[0].unresolved = 1;
expr->smp->arg_p[0].data.str.str = strdup("");
expr->smp->arg_p[0].data.str.size = 1;
expr->smp->arg_p[0].data.str.len = 0;
al->ctx = ARGC_ACL;
al->kw = expr->kw;
al->conv = NULL;
arg_list_add(al, &expr->smp->arg_p[0], 0);
expr->smp->arg_p[1].type = ARGT_STOP;
}
else if (ARGM(expr->smp->fetch->arg_mask)) {
/* there were some mandatory arguments */
memprintf(err, "ACL keyword '%s' expects %d arguments", expr->kw, ARGM(expr->smp->fetch->arg_mask));
goto out_free_expr;
}
}
else {
if (arg ) {
/* no argument expected */
memprintf(err, "ACL keyword '%s' takes no argument", expr->kw);
goto out_free_expr;
}
}
/* Now process the converters if any. We have two supported syntaxes
* for the converters, which can be combined :
* - comma-delimited list of converters just after the keyword and args ;
* - one converter per keyword
* The combination allows to have each keyword being a comma-delimited
* series of converters.
*
* We want to process the former first, then the latter. For this we start
* from the beginning of the supposed place in the exiting conv chain, which
* starts at the last comma (endt).
*/
/* look for the begining of the converters list */
if (arg)
arg = strchr(arg, ',');
else
arg = strchr(args[0], ',');
if (arg) {
prev_type = expr->smp->fetch->out_type;
while (1) {
struct sample_conv *conv;
struct sample_conv_expr *conv_expr;
if (*arg == ')') /* skip last closing parenthesis */
arg++;
if (*arg && *arg != ',') {
if (ckw)
memprintf(err, "ACL keyword '%s' : missing comma after conv keyword '%s'.",
expr->kw, ckw);
else
memprintf(err, "ACL keyword '%s' : missing comma after fetch keyword.",
expr->kw);
goto out_free_expr;
}
while (*arg == ',') /* then trailing commas */
arg++;
begw = arg; /* start of conv keyword */
if (!*begw)
/* none ? end of converters */
break;
for (endw = begw; *endw && *endw != '(' && *endw != ','; endw++);
free(ckw);
ckw = my_strndup(begw, endw - begw);
conv = find_sample_conv(begw, endw - begw);
if (!conv) {
/* Unknown converter method */
memprintf(err, "ACL keyword '%s' : unknown conv method '%s'.",
expr->kw, ckw);
goto out_free_expr;
}
arg = endw;
if (*arg == '(') {
/* look for the end of this term */
while (*arg && *arg != ')')
arg++;
if (*arg != ')') {
memprintf(err, "ACL keyword '%s' : syntax error: missing ')' after conv keyword '%s'.",
expr->kw, ckw);
goto out_free_expr;
}
}
if (conv->in_type >= SMP_TYPES || conv->out_type >= SMP_TYPES) {
memprintf(err, "ACL keyword '%s' : returns type of conv method '%s' is unknown.",
expr->kw, ckw);
goto out_free_expr;
}
/* If impossible type conversion */
if (!sample_casts[prev_type][conv->in_type]) {
memprintf(err, "ACL keyword '%s' : conv method '%s' cannot be applied.",
expr->kw, ckw);
goto out_free_expr;
}
prev_type = conv->out_type;
conv_expr = calloc(1, sizeof(struct sample_conv_expr));
if (!conv_expr)
goto out_free_expr;
LIST_ADDQ(&(expr->smp->conv_exprs), &(conv_expr->list));
conv_expr->conv = conv;
if (arg != endw) {
char *err_msg = NULL;
int err_arg;
if (!conv->arg_mask) {
memprintf(err, "ACL keyword '%s' : conv method '%s' does not support any args.",
expr->kw, ckw);
goto out_free_expr;
}
al->kw = expr->smp->fetch->kw;
al->conv = conv_expr->conv->kw;
if (make_arg_list(endw + 1, arg - endw - 1, conv->arg_mask, &conv_expr->arg_p, &err_msg, NULL, &err_arg, al) < 0) {
memprintf(err, "ACL keyword '%s' : invalid arg %d in conv method '%s' : %s.",
expr->kw, err_arg+1, ckw, err_msg);
free(err_msg);
goto out_free_expr;
}
if (!conv_expr->arg_p)
conv_expr->arg_p = empty_arg_list;
if (conv->val_args && !conv->val_args(conv_expr->arg_p, conv, &err_msg)) {
memprintf(err, "ACL keyword '%s' : invalid args in conv method '%s' : %s.",
expr->kw, ckw, err_msg);
free(err_msg);
goto out_free_expr;
}
}
else if (ARGM(conv->arg_mask)) {
memprintf(err, "ACL keyword '%s' : missing args for conv method '%s'.",
expr->kw, ckw);
goto out_free_expr;
}
}
}
}
/* Additional check to protect against common mistakes */
cur_type = smp_expr_output_type(expr->smp);
if (expr->pat.parse && cur_type != SMP_T_BOOL && !*args[1]) {
Warning("parsing acl keyword '%s' :\n"
" no pattern to match against were provided, so this ACL will never match.\n"
" If this is what you intended, please add '--' to get rid of this warning.\n"
" If you intended to match only for existence, please use '-m found'.\n"
" If you wanted to force an int to match as a bool, please use '-m bool'.\n"
"\n",
args[0]);
}
args++;
/* check for options before patterns. Supported options are :
* -i : ignore case for all patterns by default
* -f : read patterns from those files
* -m : force matching method (must be used before -f)
* -- : everything after this is not an option
*/
patflags = 0;
while (**args == '-') {
if ((*args)[1] == 'i')
patflags |= PAT_F_IGNORE_CASE;
else if ((*args)[1] == 'f') {
if (!expr->pat.parse) {
memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
goto out_free_expr;
}
if (!pattern_read_from_file(&expr->pat, args[1], patflags | PAT_F_FROM_FILE, err))
goto out_free_expr;
args++;
}
else if ((*args)[1] == 'm') {
int idx;
if (!LIST_ISEMPTY(&expr->pat.patterns) || !eb_is_empty(&expr->pat.pattern_tree)) {
memprintf(err, "'-m' must only be specified before patterns and files in parsing ACL expression");
goto out_free_expr;
}
idx = pat_find_match_name(args[1]);
if (idx < 0) {
memprintf(err, "unknown matching method '%s' when parsing ACL expression", args[1]);
goto out_free_expr;
}
/* Note: -m found is always valid, bool/int are compatible, str/bin/reg/len are compatible */
if (idx == PAT_MATCH_FOUND || /* -m found */
((idx == PAT_MATCH_BOOL || idx == PAT_MATCH_INT) && /* -m bool/int */
(cur_type == SMP_T_BOOL ||
cur_type == SMP_T_UINT ||
cur_type == SMP_T_SINT)) ||
(idx == PAT_MATCH_IP && /* -m ip */
(cur_type == SMP_T_IPV4 ||
cur_type == SMP_T_IPV6)) ||
((idx == PAT_MATCH_BIN || idx == PAT_MATCH_LEN || idx == PAT_MATCH_STR ||
idx == PAT_MATCH_BEG || idx == PAT_MATCH_SUB || idx == PAT_MATCH_DIR ||
idx == PAT_MATCH_DOM || idx == PAT_MATCH_END || idx == PAT_MATCH_REG) && /* strings */
(cur_type == SMP_T_STR ||
cur_type == SMP_T_BIN ||
cur_type == SMP_T_CSTR ||
cur_type == SMP_T_CBIN))) {
expr->pat.parse = pat_parse_fcts[idx];
expr->pat.match = pat_match_fcts[idx];
}
else {
memprintf(err, "matching method '%s' cannot be used with fetch keyword '%s'", args[1], expr->kw);
goto out_free_expr;
}
args++;
}
else if ((*args)[1] == '-') {
args++;
break;
}
else
break;
args++;
}
if (!expr->pat.parse) {
memprintf(err, "matching method must be specified first (using '-m') when using a sample fetch of this type ('%s')", expr->kw);
goto out_free_expr;
}
/* now parse all patterns */
opaque = 0;
while (**args) {
int ret;
pattern = (struct pattern *)calloc(1, sizeof(*pattern));
if (!pattern) {
memprintf(err, "out of memory when parsing ACL pattern");
goto out_free_expr;
}
pattern->flags = patflags;
pattern->type = SMP_TYPES; /* unspecified type */
ret = expr->pat.parse(args, pattern, NULL, &opaque, err);
if (!ret)
goto out_free_pattern;
LIST_ADDQ(&expr->pat.patterns, &pattern->list);
args += ret;
}
return expr;
out_free_pattern:
pattern_free(pattern);
out_free_expr:
prune_acl_expr(expr);
free(expr);
free(ckw);
out_return:
return NULL;
}
/* Purge everything in the acl <acl>, then return <acl>. */
struct acl *prune_acl(struct acl *acl) {
struct acl_expr *expr, *exprb;
free(acl->name);
list_for_each_entry_safe(expr, exprb, &acl->expr, list) {
LIST_DEL(&expr->list);
prune_acl_expr(expr);
free(expr);
}
return acl;
}
/* Parse an ACL with the name starting at <args>[0], and with a list of already
* known ACLs in <acl>. If the ACL was not in the list, it will be added.
* A pointer to that ACL is returned. If the ACL has an empty name, then it's
* an anonymous one and it won't be merged with any other one. If <err> is not
* NULL, it will be filled with an appropriate error. This pointer must be
* freeable or NULL. <al> is the arg_list serving as a head for unresolved
* dependencies.
*
* args syntax: <aclname> <acl_expr>
*/
struct acl *parse_acl(const char **args, struct list *known_acl, char **err, struct arg_list *al)
{
__label__ out_return, out_free_acl_expr, out_free_name;
struct acl *cur_acl;
struct acl_expr *acl_expr;
char *name;
const char *pos;
if (**args && (pos = invalid_char(*args))) {
memprintf(err, "invalid character in ACL name : '%c'", *pos);
goto out_return;
}
acl_expr = parse_acl_expr(args + 1, err, al);
if (!acl_expr) {
/* parse_acl_expr will have filled <err> here */
goto out_return;
}
/* Check for args beginning with an opening parenthesis just after the
* subject, as this is almost certainly a typo. Right now we can only
* emit a warning, so let's do so.
*/
if (!strchr(args[1], '(') && *args[2] == '(')
Warning("parsing acl '%s' :\n"
" matching '%s' for pattern '%s' is likely a mistake and probably\n"
" not what you want. Maybe you need to remove the extraneous space before '('.\n"
" If you are really sure this is not an error, please insert '--' between the\n"
" match and the pattern to make this warning message disappear.\n",
args[0], args[1], args[2]);
if (*args[0])
cur_acl = find_acl_by_name(args[0], known_acl);
else
cur_acl = NULL;
if (!cur_acl) {
name = strdup(args[0]);
if (!name) {
memprintf(err, "out of memory when parsing ACL");
goto out_free_acl_expr;
}
cur_acl = (struct acl *)calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL) {
memprintf(err, "out of memory when parsing ACL");
goto out_free_name;
}
LIST_INIT(&cur_acl->expr);
LIST_ADDQ(known_acl, &cur_acl->list);
cur_acl->name = name;
}
/* We want to know what features the ACL needs (typically HTTP parsing),
* and where it may be used. If an ACL relies on multiple matches, it is
* OK if at least one of them may match in the context where it is used.
*/
cur_acl->use |= acl_expr->smp->fetch->use;
cur_acl->val |= acl_expr->smp->fetch->val;
LIST_ADDQ(&cur_acl->expr, &acl_expr->list);
return cur_acl;
out_free_name:
free(name);
out_free_acl_expr:
prune_acl_expr(acl_expr);
free(acl_expr);
out_return:
return NULL;
}
/* Some useful ACLs provided by default. Only those used are allocated. */
const struct {
const char *name;
const char *expr[4]; /* put enough for longest expression */
} default_acl_list[] = {
{ .name = "TRUE", .expr = {"always_true",""}},
{ .name = "FALSE", .expr = {"always_false",""}},
{ .name = "LOCALHOST", .expr = {"src","127.0.0.1/8",""}},
{ .name = "HTTP", .expr = {"req_proto_http",""}},
{ .name = "HTTP_1.0", .expr = {"req_ver","1.0",""}},
{ .name = "HTTP_1.1", .expr = {"req_ver","1.1",""}},
{ .name = "METH_CONNECT", .expr = {"method","CONNECT",""}},
{ .name = "METH_GET", .expr = {"method","GET","HEAD",""}},
{ .name = "METH_HEAD", .expr = {"method","HEAD",""}},
{ .name = "METH_OPTIONS", .expr = {"method","OPTIONS",""}},
{ .name = "METH_POST", .expr = {"method","POST",""}},
{ .name = "METH_TRACE", .expr = {"method","TRACE",""}},
{ .name = "HTTP_URL_ABS", .expr = {"url_reg","^[^/:]*://",""}},
{ .name = "HTTP_URL_SLASH", .expr = {"url_beg","/",""}},
{ .name = "HTTP_URL_STAR", .expr = {"url","*",""}},
{ .name = "HTTP_CONTENT", .expr = {"hdr_val(content-length)","gt","0",""}},
{ .name = "RDP_COOKIE", .expr = {"req_rdp_cookie_cnt","gt","0",""}},
{ .name = "REQ_CONTENT", .expr = {"req_len","gt","0",""}},
{ .name = "WAIT_END", .expr = {"wait_end",""}},
{ .name = NULL, .expr = {""}}
};
/* Find a default ACL from the default_acl list, compile it and return it.
* If the ACL is not found, NULL is returned. In theory, it cannot fail,
* except when default ACLs are broken, in which case it will return NULL.
* If <known_acl> is not NULL, the ACL will be queued at its tail. If <err> is
* not NULL, it will be filled with an error message if an error occurs. This
* pointer must be freeable or NULL. <al> is an arg_list serving as a list head
* to report missing dependencies.
*/
static struct acl *find_acl_default(const char *acl_name, struct list *known_acl,
char **err, struct arg_list *al)
{
__label__ out_return, out_free_acl_expr, out_free_name;
struct acl *cur_acl;
struct acl_expr *acl_expr;
char *name;
int index;
for (index = 0; default_acl_list[index].name != NULL; index++) {
if (strcmp(acl_name, default_acl_list[index].name) == 0)
break;
}
if (default_acl_list[index].name == NULL) {
memprintf(err, "no such ACL : '%s'", acl_name);
return NULL;
}
acl_expr = parse_acl_expr((const char **)default_acl_list[index].expr, err, al);
if (!acl_expr) {
/* parse_acl_expr must have filled err here */
goto out_return;
}
name = strdup(acl_name);
if (!name) {
memprintf(err, "out of memory when building default ACL '%s'", acl_name);
goto out_free_acl_expr;
}
cur_acl = (struct acl *)calloc(1, sizeof(*cur_acl));
if (cur_acl == NULL) {
memprintf(err, "out of memory when building default ACL '%s'", acl_name);
goto out_free_name;
}
cur_acl->name = name;
cur_acl->use |= acl_expr->smp->fetch->use;
cur_acl->val |= acl_expr->smp->fetch->val;
LIST_INIT(&cur_acl->expr);
LIST_ADDQ(&cur_acl->expr, &acl_expr->list);
if (known_acl)
LIST_ADDQ(known_acl, &cur_acl->list);
return cur_acl;
out_free_name:
free(name);
out_free_acl_expr:
prune_acl_expr(acl_expr);
free(acl_expr);
out_return:
return NULL;
}
/* Purge everything in the acl_cond <cond>, then return <cond>. */
struct acl_cond *prune_acl_cond(struct acl_cond *cond)
{
struct acl_term_suite *suite, *tmp_suite;
struct acl_term *term, *tmp_term;
/* iterate through all term suites and free all terms and all suites */
list_for_each_entry_safe(suite, tmp_suite, &cond->suites, list) {
list_for_each_entry_safe(term, tmp_term, &suite->terms, list)
free(term);
free(suite);
}
return cond;
}
/* Parse an ACL condition starting at <args>[0], relying on a list of already
* known ACLs passed in <known_acl>. The new condition is returned (or NULL in
* case of low memory). Supports multiple conditions separated by "or". If
* <err> is not NULL, it will be filled with a pointer to an error message in
* case of error, that the caller is responsible for freeing. The initial
* location must either be freeable or NULL. The list <al> serves as a list head
* for unresolved dependencies.
*/
struct acl_cond *parse_acl_cond(const char **args, struct list *known_acl,
enum acl_cond_pol pol, char **err, struct arg_list *al)
{
__label__ out_return, out_free_suite, out_free_term;
int arg, neg;
const char *word;
struct acl *cur_acl;
struct acl_term *cur_term;
struct acl_term_suite *cur_suite;
struct acl_cond *cond;
unsigned int suite_val;
cond = (struct acl_cond *)calloc(1, sizeof(*cond));
if (cond == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_return;
}
LIST_INIT(&cond->list);
LIST_INIT(&cond->suites);
cond->pol = pol;
cond->val = 0;
cur_suite = NULL;
suite_val = ~0U;
neg = 0;
for (arg = 0; *args[arg]; arg++) {
word = args[arg];
/* remove as many exclamation marks as we can */
while (*word == '!') {
neg = !neg;
word++;
}
/* an empty word is allowed because we cannot force the user to
* always think about not leaving exclamation marks alone.
*/
if (!*word)
continue;
if (strcasecmp(word, "or") == 0 || strcmp(word, "||") == 0) {
/* new term suite */
cond->val |= suite_val;
suite_val = ~0U;
cur_suite = NULL;
neg = 0;
continue;
}
if (strcmp(word, "{") == 0) {
/* we may have a complete ACL expression between two braces,
* find the last one.
*/
int arg_end = arg + 1;
const char **args_new;
while (*args[arg_end] && strcmp(args[arg_end], "}") != 0)
arg_end++;
if (!*args[arg_end]) {
memprintf(err, "missing closing '}' in condition");
goto out_free_suite;
}
args_new = calloc(1, (arg_end - arg + 1) * sizeof(*args_new));
if (!args_new) {
memprintf(err, "out of memory when parsing condition");
goto out_free_suite;
}
args_new[0] = "";
memcpy(args_new + 1, args + arg + 1, (arg_end - arg) * sizeof(*args_new));
args_new[arg_end - arg] = "";
cur_acl = parse_acl(args_new, known_acl, err, al);
free(args_new);
if (!cur_acl) {
/* note that parse_acl() must have filled <err> here */
goto out_free_suite;
}
word = args[arg + 1];
arg = arg_end;
}
else {
/* search for <word> in the known ACL names. If we do not find
* it, let's look for it in the default ACLs, and if found, add
* it to the list of ACLs of this proxy. This makes it possible
* to override them.
*/
cur_acl = find_acl_by_name(word, known_acl);
if (cur_acl == NULL) {
cur_acl = find_acl_default(word, known_acl, err, al);
if (cur_acl == NULL) {
/* note that find_acl_default() must have filled <err> here */
goto out_free_suite;
}
}
}
cur_term = (struct acl_term *)calloc(1, sizeof(*cur_term));
if (cur_term == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_free_suite;
}
cur_term->acl = cur_acl;
cur_term->neg = neg;
/* Here it is a bit complex. The acl_term_suite is a conjunction
* of many terms. It may only be used if all of its terms are
* usable at the same time. So the suite's validity domain is an
* AND between all ACL keywords' ones. But, the global condition
* is valid if at least one term suite is OK. So it's an OR between
* all of their validity domains. We could emit a warning as soon
* as suite_val is null because it means that the last ACL is not
* compatible with the previous ones. Let's remain simple for now.
*/
cond->use |= cur_acl->use;
suite_val &= cur_acl->val;
if (!cur_suite) {
cur_suite = (struct acl_term_suite *)calloc(1, sizeof(*cur_suite));
if (cur_suite == NULL) {
memprintf(err, "out of memory when parsing condition");
goto out_free_term;
}
LIST_INIT(&cur_suite->terms);
LIST_ADDQ(&cond->suites, &cur_suite->list);
}
LIST_ADDQ(&cur_suite->terms, &cur_term->list);
neg = 0;
}
cond->val |= suite_val;
return cond;
out_free_term:
free(cur_term);
out_free_suite:
prune_acl_cond(cond);
free(cond);
out_return:
return NULL;
}
/* Builds an ACL condition starting at the if/unless keyword. The complete
* condition is returned. NULL is returned in case of error or if the first
* word is neither "if" nor "unless". It automatically sets the file name and
* the line number in the condition for better error reporting, and sets the
* HTTP intiailization requirements in the proxy. If <err> is not NULL, it will
* be filled with a pointer to an error message in case of error, that the
* caller is responsible for freeing. The initial location must either be
* freeable or NULL.
*/
struct acl_cond *build_acl_cond(const char *file, int line, struct proxy *px, const char **args, char **err)
{
enum acl_cond_pol pol = ACL_COND_NONE;
struct acl_cond *cond = NULL;
if (err)
*err = NULL;
if (!strcmp(*args, "if")) {
pol = ACL_COND_IF;
args++;
}
else if (!strcmp(*args, "unless")) {
pol = ACL_COND_UNLESS;
args++;
}
else {
memprintf(err, "conditions must start with either 'if' or 'unless'");
return NULL;
}
cond = parse_acl_cond(args, &px->acl, pol, err, &px->conf.args);
if (!cond) {
/* note that parse_acl_cond must have filled <err> here */
return NULL;
}
cond->file = file;
cond->line = line;
px->http_needed |= !!(cond->use & SMP_USE_HTTP_ANY);
return cond;
}
/* Execute condition <cond> and return either ACL_TEST_FAIL, ACL_TEST_MISS or
* ACL_TEST_PASS depending on the test results. ACL_TEST_MISS may only be
* returned if <opt> does not contain SMP_OPT_FINAL, indicating that incomplete
* data is being examined. The function automatically sets SMP_OPT_ITERATE. This
* function only computes the condition, it does not apply the polarity required
* by IF/UNLESS, it's up to the caller to do this using something like this :
*
* res = acl_pass(res);
* if (res == ACL_TEST_MISS)
* return 0;
* if (cond->pol == ACL_COND_UNLESS)
* res = !res;
*/
enum acl_test_res acl_exec_cond(struct acl_cond *cond, struct proxy *px, struct session *l4, void *l7, unsigned int opt)
{
__label__ fetch_next;
struct acl_term_suite *suite;
struct acl_term *term;
struct acl_expr *expr;
struct acl *acl;
struct sample smp;
enum acl_test_res acl_res, suite_res, cond_res;
/* ACLs are iterated over all values, so let's always set the flag to
* indicate this to the fetch functions.
*/
opt |= SMP_OPT_ITERATE;
/* We're doing a logical OR between conditions so we initialize to FAIL.
* The MISS status is propagated down from the suites.
*/
cond_res = ACL_TEST_FAIL;
list_for_each_entry(suite, &cond->suites, list) {
/* Evaluate condition suite <suite>. We stop at the first term
* which returns ACL_TEST_FAIL. The MISS status is still propagated
* in case of uncertainty in the result.
*/
/* we're doing a logical AND between terms, so we must set the
* initial value to PASS.
*/
suite_res = ACL_TEST_PASS;
list_for_each_entry(term, &suite->terms, list) {
acl = term->acl;
/* FIXME: use cache !
* check acl->cache_idx for this.
*/
/* ACL result not cached. Let's scan all the expressions
* and use the first one to match.
*/
acl_res = ACL_TEST_FAIL;
list_for_each_entry(expr, &acl->expr, list) {
/* we need to reset context and flags */
memset(&smp, 0, sizeof(smp));
fetch_next:
if (!sample_process(px, l4, l7, opt, expr->smp, &smp)) {
/* maybe we could not fetch because of missing data */
if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
acl_res |= ACL_TEST_MISS;
continue;
}
acl_res |= pat2acl(pattern_exec_match(&expr->pat, &smp, NULL));
/*
* OK now acl_res holds the result of this expression
* as one of ACL_TEST_FAIL, ACL_TEST_MISS or ACL_TEST_PASS.
*
* Then if (!MISS) we can cache the result, and put
* (smp.flags & SMP_F_VOLATILE) in the cache flags.
*
* FIXME: implement cache.
*
*/
/* we're ORing these terms, so a single PASS is enough */
if (acl_res == ACL_TEST_PASS)
break;
if (smp.flags & SMP_F_NOT_LAST)
goto fetch_next;
/* sometimes we know the fetched data is subject to change
* later and give another chance for a new match (eg: request
* size, time, ...)
*/
if (smp.flags & SMP_F_MAY_CHANGE && !(opt & SMP_OPT_FINAL))
acl_res |= ACL_TEST_MISS;
}
/*
* Here we have the result of an ACL (cached or not).
* ACLs are combined, negated or not, to form conditions.
*/
if (term->neg)
acl_res = acl_neg(acl_res);
suite_res &= acl_res;
/* we're ANDing these terms, so a single FAIL or MISS is enough */
if (suite_res != ACL_TEST_PASS)
break;
}
cond_res |= suite_res;
/* we're ORing these terms, so a single PASS is enough */
if (cond_res == ACL_TEST_PASS)
break;
}
return cond_res;
}
/* Returns a pointer to the first ACL conflicting with usage at place <where>
* which is one of the SMP_VAL_* bits indicating a check place, or NULL if
* no conflict is found. Only full conflicts are detected (ACL is not usable).
* Use the next function to check for useless keywords.
*/
const struct acl *acl_cond_conflicts(const struct acl_cond *cond, unsigned int where)
{
struct acl_term_suite *suite;
struct acl_term *term;
struct acl *acl;
list_for_each_entry(suite, &cond->suites, list) {
list_for_each_entry(term, &suite->terms, list) {
acl = term->acl;
if (!(acl->val & where))
return acl;
}
}
return NULL;
}
/* Returns a pointer to the first ACL and its first keyword to conflict with
* usage at place <where> which is one of the SMP_VAL_* bits indicating a check
* place. Returns true if a conflict is found, with <acl> and <kw> set (if non
* null), or false if not conflict is found. The first useless keyword is
* returned.
*/
int acl_cond_kw_conflicts(const struct acl_cond *cond, unsigned int where, struct acl const **acl, char const **kw)
{
struct acl_term_suite *suite;
struct acl_term *term;
struct acl_expr *expr;
list_for_each_entry(suite, &cond->suites, list) {
list_for_each_entry(term, &suite->terms, list) {
list_for_each_entry(expr, &term->acl->expr, list) {
if (!(expr->smp->fetch->val & where)) {
if (acl)
*acl = term->acl;
if (kw)
*kw = expr->kw;
return 1;
}
}
}
}
return 0;
}
/*
* Find targets for userlist and groups in acl. Function returns the number
* of errors or OK if everything is fine. It must be called only once sample
* fetch arguments have been resolved (after smp_resolve_args()).
*/
int acl_find_targets(struct proxy *p)
{
struct acl *acl;
struct acl_expr *expr;
struct pattern *pattern;
int cfgerr = 0;
list_for_each_entry(acl, &p->acl, list) {
list_for_each_entry(expr, &acl->expr, list) {
if (!strcmp(expr->kw, "http_auth_group")) {
/* Note: the ARGT_USR argument may only have been resolved earlier
* by smp_resolve_args().
*/
if (expr->smp->arg_p->unresolved) {
Alert("Internal bug in proxy %s: %sacl %s %s() makes use of unresolved userlist '%s'. Please report this.\n",
p->id, *acl->name ? "" : "anonymous ", acl->name, expr->kw, expr->smp->arg_p->data.str.str);
cfgerr++;
continue;
}
if (LIST_ISEMPTY(&expr->pat.patterns)) {
Alert("proxy %s: acl %s %s(): no groups specified.\n",
p->id, acl->name, expr->kw);
cfgerr++;
continue;
}
list_for_each_entry(pattern, &expr->pat.patterns, list) {
/* this keyword only has one argument */
pattern->val.group_mask = auth_resolve_groups(expr->smp->arg_p->data.usr, pattern->ptr.str);
if (!pattern->val.group_mask) {
Alert("proxy %s: acl %s %s(): invalid group '%s'.\n",
p->id, acl->name, expr->kw, pattern->ptr.str);
cfgerr++;
}
free(pattern->ptr.str);
pattern->ptr.str = NULL;
pattern->len = 0;
}
}
}
}
return cfgerr;
}
/* initializes ACLs by resolving the sample fetch names they rely upon.
* Returns 0 on success, otherwise an error.
*/
int init_acl()
{
int err = 0;
int index;
const char *name;
struct acl_kw_list *kwl;
struct sample_fetch *smp;
list_for_each_entry(kwl, &acl_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
name = kwl->kw[index].fetch_kw;
if (!name)
name = kwl->kw[index].kw;
smp = find_sample_fetch(name, strlen(name));
if (!smp) {
Alert("Critical internal error: ACL keyword '%s' relies on sample fetch '%s' which was not registered!\n",
kwl->kw[index].kw, name);
err++;
continue;
}
kwl->kw[index].smp = smp;
}
}
return err;
}
/************************************************************************/
/* All supported sample and ACL keywords must be declared here. */
/************************************************************************/
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
*/
static struct acl_kw_list acl_kws = {ILH, {
{ /* END */ },
}};
__attribute__((constructor))
static void __acl_init(void)
{
acl_register_keywords(&acl_kws);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/
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